maven build docker image

1. add docker maven to pom.xml

        <plugin>
            <groupId>com.spotify</groupId>
            <artifactId>docker-maven-plugin</artifactId>
            <version>0.4.13</version>
            <configuration>
                <imageName>${project.name}:${project.version}</imageName>
                <baseImage>java</baseImage>
                <entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
                <resources>
                    <resource>
                        <targetPath>/</targetPath>
                        <directory>${project.build.directory}</directory>
                        <include>${project.build.finalName}.jar</include>
                    </resource>
                </resources>
                <!--docker宿主机的ip，要为docker开通tcp访问才有效-->
                <!--<dockerHost>http://8.129.181.68:2375</dockerHost>-->
                <dockerHost>http://localhost:2375</dockerHost>
            </configuration>
        </plugin>

2. exec cmd below
   sudo mvn clean install
   sudo mvn docker:build